This invention relates to removal tools and more particularly tools for removing filter membranes from housings.
Ceramic membrane ultrafiltration has been used for a number of years in the laboratory to purify materials. Recently ceramic membrane ultrafiltration has been adapted for the purification of large quantities of compounds in chemical processing plants. Because of the large scales involved the ultrafiltration apparatuses are different in configuration from laboratory ultrafiltration systems. One type of large-scale ultrafiltration apparatus comprises a canister housing including a plurality of parallel running filter membranes. The membranes pass through holes at the inlet and outlet of the empty canister. Rubber grommets fitted to the membranes at the canister holes provide an extremely secure fit. The solution or suspension to be filtered cycles repeatedly through bores in the filter membrane. The permeate is filtered through the porous ceramic membrane into the canister housing interior and exits the canister housing interior through additional outlets. Typically provision is made for cleaning the ceramic membranes through these additional outlets by backflushing.
During use the membranes tend to become "locked" in place. In fact, because the membranes are typically made of a brittle ceramic, it can be difficult to remove the membranes from the canister without breaking them. One removal technique utilizes a hammer and polypropylene pin to drive the membrane through the holes. However, typically this results in a broken membrane.
Because these membranes are expensive there is a continuing search in this field of art for devices for successfully removing membranes from filter housings.